Fuze



F. B. HALE Jan. 5, 1954 FUZE 2 Sheets-Sheet l Filed Jan. 3, 1950 iwucmfoz Fran/71: Hav/Ze F. B. HALE `Fan. 5, 1954 FUZE 2 Sheets-Sheet 2 Filed Jan. 3, 1950 f ik.)

nucnroz Frank Z5. Ha/Ze Patented Jan. 5, 1954 aegee FUZE Frank B. Hale, Bel Air, Md., assignor to the United States of America as represented by the Secretary of the Army (Granted under Title 35, U. S. Code (1952),

sec. 266) 11 Claims.

The invention described herein may be manufactured and used by or for the Government, for governmental purposes, without the payment to me of any royalties thereon.

This invention relates to actuating devices in general, and more particularly has reference to actuating devices for projectiles.

Previous to this time, as in World Wars I and Il, and in training and maneuvers of armed forces, numerous incidents have occurred wherein premature actuation ci a fuze mechanism has detonated the complete round with resultant infiiction of serious casualties upon members of the gun crew, or other strategic groups operating these or similar ordnance pieces. The premature explosions of rounds often took place in the muzzle of a gun, or within close proximity of the muzzle, with corresponding danger to personnel in the immediate vicinity. In addition, a projectile leaving a bore or barrel might strike an object in the gun position and detonate with similar disastrous consequences to personnel in the approximate area.

This invention is intended to eliminate such hazardous conditions by providing a fuze which is incapable of being actuated during handling and for a safe period after the round has left the ordnance piece.

rlhe present invention is directed to fuzes for mounting on projectiles used in muzzle loading and breach loading ordnance pieces, rockets, bombs, and other instruments employed to obtain destructive results in military and peace-time practices, wherein the projectile rotates during its iiight. The invention resides generally in an arming delay that is accomplished by a mechanical method employing the principle that a movable internal component of a rotating body will tend to move sc as to place its center of mass as distant from the axis of rotation as possible. In using this principle, the detonating means is placed in a rotor which is weighted with a slug of heavy material, such as lead, on one side and a heavy liquid capsule on the opposite side. The amount, weight, and position of the heavy liquid all tend to locate the center of mass of the rotor on the liquid side of the axis of rotation of the rotor. The force of setback causes a small hole to be pierced in the top of the capsule and thereby allows the liquid to escape therefrom. When the liquid leaves the rotor, the center of mass thereof is shifted to the opposite side of the axis of rotation adjacent the heavy slug whereby the rotor turns and moves the detonating means into the armed position. The delay in arming is that interval of time which is required for the liquid to ow from the capsule. The time canbe controlled by the size of the hole through which the liquid flows and by the viscosity of the liquid.

An object of this invention is to provide a fuze which may be safely transported and handled.

Another object of this invention is to provide a fuze which is protected against inadvertent operation in the barrel of an ordnance piece.

Another object is to provide a fuze which is positively locked against inadvertent operation prior to ring, and the functioning of which is insured after subjection to the normal shock or other action permitted to turn.

Another object is to provide novel means of delaying the arming of the fuze until it has traveled sufcient distance from the gun so as to eliminate the hazard attendant upon having the shell drop in the vicinity of the firing piece.

A further object is to provide a fuze in which an instantaneous or a delayed detonator may be used, and in which the desired detonator may be preselected prior to the insertion of the round in the ordnance piece.

Other objects and advantages of this invention will become apparent from the following description, taken in connection with the accompanying drawings in Which:

Figure 1 is a side view of the fuze forming the subject matter of this invention.

Figure 2 is a sectional view taken on the line I I of Fig. 1, showing the relation of the parts of the fuze in the unarmed position.

Figure 3 is a cross-section view of Fig. 1, taken on line 2 2, with part of the rotor broken away to show the armed locking pins.

Figure 4 is a side View, partly in section, taken on line 3 3 of Fig. 3, showing the relation of the parts of the fuze prior to discharge of the projectile on which it is mounted.

Figure 5 is a side view, partly in section, taken on line 4 4 of Fig. 3.

Figure 6 is a side view, partly in section, taken on line 3 3 of Fig. 3, showing the relation of the parts of the fuze after the discharge of the projectile and preparatory to movement of the parts into re position.

Figure '7 is a cross-sectional View taken on line 5 5` of Fig. 1, showing the position of the rotor with the quick detonator in armed position.

Figure 8 is a cross-sectional view taken on line 5 5 of Fig. 1, showing the position of the rotor with the delay detonator in armed position.

Figure 9 is a sectional view taken on line I l a of Fig. l, showing the relation of the parts of the fuze on impact with the target.

Figure l is a side View, partly in section, taken on line ivi-3 of Fig. 2, showing the position of the selection mechanism when set for delay action.

Referring more particularly to the drawings, in which the same and similar elements are designated by like numerals: Fig. 1 represents a fuze comprising a head or cap section M, a body section 9, and bottom section i. All sections are threadedly engaged with their adjacent sections, as at t3 and I0.

Referring to Fig. 2: the cap section is made in the form of a frustum of a cone, with a stem portion extending from the larger base. The stem portion is threaded for securing reception in a central slot in the body section. A bore 45 extends longitudinally through the cap section, reoei-ving thereon cylindrical firing pin 43. Bore is counter bored, as at 46, and receives therein a spiral spring i which encircles the firing pin. The cap section has a cutaway portion on its small base to form a chamber 4'! therein which is centrally aligned with counter bore 4S. Firing pin L18 extends through chamber 41, counter bore df, and bore 135 and is received in a slot in the body section. An annular collar i9 is attached to the firing pin along the extending portion thereof and abuts against the lower end of the stem, thereby limiting the outward movement of said ring pin. The upper end of the firing pin is threaded and has secured thereto the firing pin head 5i), which is accommodated in chamber 6i?. Spiral spring 5I rests upon the base of counter bore d6, encircles the nring pin, and abuts against the head 553 and is thereby held under compression. It is thus seen that the firing pin is free to move longitudinally within the cap section and will move downward, against spring 0,8, upon application of pressure on the head 50; the outward movement thereof is limited by collar t8 and the base of the stem.

The bottom section 2, like the cap section, is made in the shape of a frustum of a cone, and has a stem portion extending from the larger base. rEhe stem portion is externally threaded for threadedly engaging the base socket of a shell. The small stem is centrally bored to threadedly receive burster tube 3 containing the burster charge 5. The base wall of the bore is centrally apertured and receives therein cup l, which is hanged at its base to retainably abut the said base wall. The cup is filled with a primer charge B. combined form the projectile actuating charge, or shell actuating charge. The small base of the bottom section is cut away to form a chamber, the walls thereof being threaded, as at Hi, to receive an extending portion of the body section. The chamber is in communication with the aperture in the base wall of the stem bore and, through this aperture, in communication with the stem bore. It is therefore clear that a detonating charge in the chamber and in alignment with the aperture would set 01T the projectile actuating means.

The body section, like the other two sections, is in the form of a frustum of a. cone, with a stern portion extending from the large base thereof. The stein is externally threaded, whereby it is threadedly received in the chamber of the bottom section. A cavity il is bored into the stem and extends some distance into the cone. The cavity side walls, Fig. 3, are formed by cutting away an The burster charge and primer charge arcuate section generated at a rst radius from an axis eccentric to the axis of the frustum, and a second arcuate sectiongenerated by a second radius from the said eccentric axis; the first and second radius being of diiferent lengths. The net result of this cut out is a cavity having a large arcuate section and a small arcuate section. The base wall of the cavity is bored and threaded along the eccentric axis and threadedly receives therein the base portion of rotor shaft I3. Rotor i2 is mounted on shaft I3 and is free to move therearound. The rotor is formed in the shape of a cylinder l 2a and has an axial bore therethrough. A second and smaller cylinder 42o is mounted on the outer periphery of the iirst cylinder. This arrangement is such that the distance between said axial bore and the furthermcst portion of the outer periphery oi the second cylinder is slightly less than the radius of the large arcuate section of the cavity. Similarly, the radius of the first cylinder is slightly less than the radius of the small arcuate section. It is thus clear that the rotor is free to revolve within the cavity through the angle generated by the large arc.

Cylinder i205 has in addition to the axial bore four bores spaced in groups of two on diametrically opposite sides of the axial bore. The rst group is located adjacent to the second cylinder i217 and recei es therein detonating charges I4 and i5. The second group receives therein slugs of heavy material it. The rotor is made from relatively light material, such as aluminum, whereby the slugs of heavy material control the position of the center of mass of the unit as a whole. Lead has been found to be an excellent heavy material, although other materials of high density may also be used. The cylinder ma has portions thereof cut away as at 52o so as to lessen the influence of the mass thereof in determining the location of center of mass. Cylinder lZb is bored to form a recess therein which receives capsule il. The capsule, Fig. 4, is lled with a liquid It and is hermetically sealed by lid I9 and gasket 20. The size of the capsule and its location in the rotor with relation to the rotational axis are such that the mass thereof offsets the mass of the lead slugs and moves the center of mass of the rotor to the detonator side. The capsule may be nlled with any liquid which remains as such over the operating temperatures. For example, water may be used, although its freezing and boiling temperatures would limit its usefulness. Compositions such as mercury or tetrachloroethane are desirable for application over a wider temperature range. These liquids may be mixed with other liquids in which there is mutual solubility so as to Vary their viscosity and other properties. I do not wish to limit myself to the liquids named herein, but merely disclose them by way of examples. From the foregoing, it will be apparent that when the shell is in night, the rotor will revolve about its eccentric axis so as to move the center of mass thereof as far away from the axis of rotation of the fuxe as is possible. it will also be apparent that if the center of mass of the rotor is changed during flight, the rotor will tend to rotate to a new position.

A circular bore 57 is formed in the body section of the fuze by cutting away a portion of the base wall of the cavity I l at one end of the large arcuate section thereof. The base wall of bore 5'! is further tapped, producing reduced bore 58 which in turn communicates with threaded aperture 59.

This system of openings serves as a receptacle for the capsule piercing means. The piercing means consists of a cylindrical cup 62, Fig. 4, having anges 52a which abut the base wall of bore 5T. One of the flanges is tapped and threaded to receive therein punch 5I, The cup member 52 is centrally apertured at the base, receiving therethrough the threaded end of punch screw 65 which is secured in aperture 53. The cup is therefore free to move up and down the punch screw. Surrounding the punch screw, between the head thereof and the base of the cup, is a spiral spring 63 which prevents the downward movement of the cup except when there is suicient pressure to compress the spring; as when the projectile is fired. Adjacent to the threaded aperture 5S the body section is longitudinally tapped to form connecting bores 5d and E5, of which bore 5d is of larger diameter. The side wall of cup E2 is also tapped to form a longitudinal bore extending the entire length of the cup and which is in alignment and communication with bores 64 and 55. Guide pin 66 is received in the aligned bores and acts to prevent the rotation of the cup 62 about the screw Gli.

In order to prevent rotation of the rotor during necessary handling of the fuze prior to firing, means are provided for locking it in the safe lposition. The means comprise horizontal bores 2l located in the stem portion of body 9, which receive therein locking pins 23 backed by springs 24, and retained in the stem by closing discs 25. The pins 23 are received in bores 22 of the rotor l2, thus holding the rotor in the unarmed position with detonators i6 and l5 out of alignment with the projectile actuating means. Upon firing, the rotation of the shell will force the pins out of bores 22 and against the spring 2li, thereby leaving the rotor free to rotate.

The detonating charges il and l5 carried by the rotor are of two types. Detonator le is of the instantaneous type, while detonator I5 is of the delayed type. They are axially disposed on the rotor so that by rotating it through a small angle, the instantaneous detonator is brought into alignment with the projectile actuating means; and by employing a larger angle of rotation, the delayed detonator is placed in the aligned position. The body section is tapped at 35 to provide a horizontal bore which is located just beyond the base wall of cavity ll in the large arcuate section as seen in Fig. 2. Cylindrical setting rod 33 is received therein, and is tapped and threaded, as at 32, to receive stop screw 3l. The side wall f bore 34 is apertured at a point 3i! in alignment with bore 32 and through which the stop screw is inserted in the said bore; the head of the stop screw extending into the large arc section of cavity ll and thereby arresting the rotation of the rotor. rEhe screw head is so positioned that when the rotor abuts it, the instantaneous detonator is in alignment with the projectile actuating means. Aperture 3G is of a longitudinal shape, as best seen in Fig. 3, and is of some depth to provide a receiving slot into which the screw head is received when the setting rod is rotated. Thus, the head of stop screw 3l may be moved into and out of its arresting position in cavity I I. When the head is in the recess 30, the rotor will rotate completely through the large arcuate section and will place delayed detonator l5 in alignment with the projectile actuating means. The small base is tapped to provide a vertical bore 35 which communicates with bore 34. Setting rod 33 is tapped at 35 to provide notches which are in alignment with bore 35 when the head of the stop screw is in recess 3! and when extending into cavity I l. Pressure means which comprise a ball 38 backed by spring 39 and a closure member are inserted in the bore 35 and serve to prevent the accidental rotation of rod 33 by spring pressing ball 38 into the notches 35. Setting rod 33 is notched at the outer head, as at 4G, to permit insertion of a screwdriver or other sharp instrument for the turning thereof. Appropriate markings lplaced adjacent the bore 34 to indicate whether the screw head is in or out of the recess, thus determining whether the instantaneous or the delayed detonator will be brought into alignment with the projectile actuating means.

Radial bores 2t are formed on the outer periphery of cylinder lila and into which are placed armed locking pins 2l and Z8, as will be seen by referring to Fig. 8. These pins coac't with notch 29, which is cut into the wall of cavity il, and into which Ythe pins will slide when rotor revolves so as to align the bore 25 and notch 2S. These bores are so positioned on the rotor that pin 2l will slide into notch 25 when the rotor abuts the head of screw 3l and thereby prevent any further rotation thereof. In this manner, instantaneous detonator is locked in the armed position. Similarly, when the rotor moves through the complete arc of travel, pin 28 will be received in notch it and the delayed detonator will be locked in the armed position; the lpin 2l having moved beyond the notch where it is thrown clear of the rotor.

The body section S has a central chamber extending downward from the small base of the conical frustum which is threaded at t3 and into which extends the stern of the cap section 4&3. The base wall of the chamber is centrally tapped to provide a bore 42, of a diameter slightly greater than collar 49 of the iiring pin, receiving therein the lower portion of the firing pin, including the said collar. The base wall of bore 62 is centrally apertured to provide communication between the bore and cavity Il, whereby the firing pin can pass in the said cavity. It will thus be clear that the ring pin can move longitudinally into and out of cavity I! with the collar and bore i2 cooperating to limit the distance of travel. Since the firing lpin, cap 8, and burster tube are all centrally located along the longitudinal axis of the fuze, it is clear that they are in alignment with each other. Further, since the movement of the firing pin is also along the longitudinal axis of the fuze, the cup and burster are in alignment with the firing pin along the axis of movement thereof.

Communicating with bore 52 are two horizontal openings 52 which are on diametrically opposite sides of the body section and which extend from the outer wall of the said section. These openings receive therein firing pin lock pins 56 which project under collar 49 and are backed by spring 55 and held in place by threaded plug 56. The lock pins serve to maintain the firing ypin in the unarmed position prior to firing the projectile. When the projectile has been fired, the rotation thereof forces the pins 54 outward against the spring 55, thereby freeing the firing pin.

Operations of this invention may be readily understood by iirst having reference to Figs. l. to 5, inclusive, wherein the fuze is shown with. the parts completely in unarmed relation. The shell rotates clockwise, as Viewed looking in the direction of its flight. Rotor l2, carrying instantaneous detonator I4 and delay detonator I5,v Fig. 4, is out of alignmentl with the projectile actuating means, so held by spring backed unarmed pin 23. Cup Si. is held against the top of bore S by spring 63, with sufficient pressure to prevent downward movement except in the case of extreme shock, as when the projectile is iired. Firing pin liti, Fig. 5, is held in place by collar 49 pressed upward against the base of the stem of cap Alli by the action of spring 5i, on ring pin head 553. Firing pin lock pin 5d backed by spring 55, projecting under collar 49, prevents longitudinal movement of the iiring pin.

When it is desired to load a projectile carrying the fuze into a weapon, setting rod 33 is turned, to either position slot lit, Fig. l, along a vertical axis for instantaneous action or along a horizontal axis for delay action. No other preparation is required.

The shock incident to ring of the projectile causes cup E52, carrying punch 5I and guided by pin E6, to slide in bore El, by reason of the inertia of the weight of the cup, thus compressing spring F53 and permitting punch el to pierce the capsule lid I9, Fig. 6. At the completion of the shock or" firing the spring 63 moves cup E2 to its original position. With the development or" sufficient centrifugal force, unarmed lock pins 23 move outward against the resistance of springs 24, thus unlocking rotor I2. The rotor is then free to move, but remains stationary because the weight and position of liquid it causes the center of mass of the rotor to be so located that the rotor tends to turn counterclockwise against the vertical wall of cavity H, Fig. 3. From the hole caused by piercing capsule lid I9, such hole being located at a point, Fig. 4, furthermost from the center of rotation of the fuze, centrifugal force acting on liquid l causes it to flow from capsule il. As the capsule loses its liquid, the center of mass of the rotor moves to the opposite side of the rotor axis, being iniiuenced by the lead inserts i6, and the rotor swings clockwise to stop screw 3i, Fig. '7; bringing instantaneous detonator lli into alignment with the ring pin and projectile actuating charge when the setting rod has been turned to quickf In this position armed lock pin 2 is caused to slide in bore 26, into notch 29, thus locking the instantaneous detonator in the armed position. In the case of using delay detonator, rotor l2 swings clockwise past the recessed stop screw Si to the opposite side of the large arcuate section. As rotor I2 swings clockwise, armed lock pin 2i in the rotor is carried past notch 29 and is thrown into cavity il and lock pin 28 enters notch 29 to lock the delay detonator in the armed position. Also, during night, ring pin lock pins are centrifugally forced outward thus leaving the firing pin free to move longitudinally within the fuze.

On impact of the projectile with an objective, the firing pin is forced downward, exploding the selected detonator and thereby igniting the projectile actuating charge to set on the projectile.

rIhus I have provided by this invention a fuze which is protected against inadvertent operation prior to use, is positively locked and unaffected by shock or movement, and which functions only when subjected to the high speed of rotation and set back attended by the firing of the weapon, thereby permitting the safe transportation and handling of projectiles on which it is mounted.

The fuze illustrated is adapted for point impact detonation and cannot arm until the liquid has been forced from the capsule. This interval being several seconds, the shell is then beyond a hazardous distance from the gun.

While I have shown and described a preferred embodiment of my invention, it is to be understood that I do not confine myself to the precise details of construction herein set forth, by way of illustration, as it is apparent that many changes and modications may be made therein by those skilled in the art without departing from the spirit of the invention or exceeding the scope of the appended claims.

I claim:

l. A uze for rotatable projectiles comprising the combination of a casing, a nring pin axially mounted therein and movable relative thereto along the said axis, a projectile actuating charge mounted in the casing along the axis or" movement of the firing pin and spaced, beyond the movable distance of the firing pin, an unbalanced rotor rotatably positioned between the said pin and said charge and eccentrieally reounted relative to the rotational axis oi the and on an axis substantially parallel thereto, a d onator carried by the rotor and movable into out of a position intermediate the Jfiring pin projectile actuating charge, within the movable distance of the ring pin, upon rotation rotor, a weight attached to the rotor shift the center of mass thereof to a pf "ion e'. ne' new radial vector with respect to rotationa center of the rotor and means to release the weight and thereby induce the rotor to turn when the fuze is rotating and thereby move the detonator into said intermediate positi i.

2. A fuze for rotatable projectiles comprising the combination of a casing, a ring pin axially mounted therein and movable relative thereto along said axis, a projectile actuating charge mounted in the casing along the axis of movement of the iiring pin and spaced therefrom, an unbalanced rotor eccentrically mounted relative to the rotational axis of the fuze, a detonator carried by the rotor and movable into and out of a position intermediate the firing pin and projectile actuating charge upon rotation of the rotor, a liquid lled container attached to the rotor to angularly shift the center of mass thereof, a punch located adjacent the container and means to cause the punch to puncture the container whereby the liquid will be removed from the rotor and thereby induce the rotor to turn when the uze is rotating whereby the detonator is moved into said intermediate position.

3. A fuze according to claim 2 wherein the container is punctured at a point furthermost from the axis of rotation of the fuze whereby the liquid is completely removed.

4. A fuze for rotatable projectiles, comprising the combination of a casing, a ring pin axially mounted therein and movable relative thereto along the said axis, a projectile actuating charge mounted in the casing along the axis or" movement of the firing pin and spaced, beyond the movable distance of the ring pin, an unbalanced rotor rotatably positioned between the said pin and said charge and eccentrically mounted rela-- tive to the rotational axis of the fuze and on an axis substantially parallel thereto, a detonator carried by the rotor and movable into and out of a position intermediate the ring pin and projectile actuating charge, within the movable distance of the ring pin, upon rotation of the rotor, a weight I'attached to the rotor to shift the center of mass thereof to a position along a new radial vector with respect to the rotational center of the assesses rotor, means to release the weight and thereby induce the rotor to turn when the fuze is rotating and thereby move the detonator into said intermediate position, and locking pins radially disposed through the casing walls and engaging the rotor to prevent accidental rotation thereof prior to ring, said locking pins being forced out of engagement with said rotor by the centrifugal force incident to rotation of the fuse during flight.

5. A fuze for rotatable projectiles comprising the combination of a casing, a firing pin axially mounted therein and movable relative thereto along said axis, a projectile actuating charge mounted in the casing along the axis of movement of the firing pin and spaced, beyond the movable distance o the firing pin, an unbalanced rotor rotatably positioned between the said pin and said charge and eccentrically mounted relative to the rotational axis of the fuze and on an axis substantially parallel thereto, a plurality of detonations circumferentially. disposed on the rotor and movable into and out of a position intermediate the nring pin and projectile actuating charge, within the movable distance of the firing pin, upon rotation of the rotor, a weight attached to the rotor to shift the center of mass thereof to a position along a new radial vector with respect to the rotational center of the rotor, means to release the weight and thereby induce the rotor to turn when the fuze is rotating and thereby move the de tonator into said intermediate position, and means movable into and out of the path of travel of the rotor and engageable therewith to limit the angle of rotation of the said rotor, said means being so positioned that upon engagement with the rotor, one of the detonators is in the said intermediate position.

6. A fuze for rotatable projectiles comprising the combination of a casing, a firing pin axially mounted therein and movable relative thereto along the said a projectile actuating charge mounted in the casing along the axis of movement of the :firing pin and spaced, beyond the movable distance of the iii-ing pin, an unbalanced rotor rotatably positioned between the said pin and said charge and eceentrically mounted relative to the rotational axis oi the fuze and on an axis substantially parallel thereto, a plurality of detonators circumferentially disposed on the rotor and movable into and out of position intermediate the iiring pin and projectile actuating charge, within the movable distance of the firing pin, upon rotation of the rotor, a weight attached to the rotor to shift the center oi mass thereof to a position along a new radial vector with respect to the rotational center of the rotor, means to release the weight and thereby induce the rotor to turn when the fuze is rotating and thereby move the detonators into said intermediate position, means movable into and out of the path of travel of the rotor and engageable therewith to limit the angle of rotation of the said rotor, said means being so positioned that upon engagement with the rotor, one of the detonators is in the said intermediate position and a member extending inward from the casing well into the path of travel of the rotor beyond the position of the said movable means to contact the rotor and arrest further movement thereof said member being so positioned that upon said Contact another of said detonators is in the said intermediate position.

7. A fuze according to claim in which the movable means extends through the outer wall of the casing whereby the said movable means can be moved into and out of the said path of travel of the rotor from the outside of the casing,

8. A fuze for rotatable projectiles comprising the combination of a casing, a liring pin axially mounted therein and movable relative thereto along the said axis, a projectile actuating charge mounted in the casing along the axis of movement of the iiring pin and spaced, beyond the movable distance of the ring pin, an unbalanced rotor rotatably positioned between the said pin and said charge and eccentrically mounted relative to the rotational axis of the Iuze and on an axis substantially parallel thereto, a detonator carried by the rotor and movable into and out of a position intermediate the firing pin and projectile actuating charge, within the movable distance of the firing pin, upon rotation oi' the rotor, a weight attached to the rotor to shirt the center of mass thereof to a position along a new radial vector with respect to the rotational center or' the rotor, means to release the weight and thereby induce the rotor to turn when the iuze is rotating and thereby move the detonator into said intermediate position, and armed locking means carried by the rotor and loclably engageable with the casing Wall when the detonator 1s moved into said intermediate position thereby preventing any subsequent backward movement of the rotor to its original position.

9. A fuze Jior rotatable projectiles comprising the combination or a casing, a firing pin axially mounted therein and movable relative thereto along the said axis, a projectile actuating charge mounted in the casing along the axis of movement of the firing pm and spaced, beyond the movable distance of the iiring pin, an unbalanced rotor rotatably positioned between the said pin and said charge and eccentricaliy mounted relative to the rotational axis of the fuze and on an axis substantially parallel thereto, a plurality of detonators circumferentially disposed on the rotor and movable into and out oia position intermediate the iiring pin and projectile actuating charge, within the movable distance of the ring pin, upon rotation of the rotor, a weight attached to the rotor to shift the center oi' mass thereof to a position along a new radial vector with respect to the rotational center oi the rotor, means to release the weight and thereby induce the rotor to turn when the fuze is rotating and thereby move the detonator into said intermediate position, means movable into and out of the path or travel of the rotor and engageable therewith to limit the angle of rotation of said rotor, said means being so positioned that upon engagement with the rotor, one of the detonators is in the said intermediate position, and armed locking means carried by the rotor and lockabiy engageable with the casing wall when the said one detonator is moved into said intermediate position thereby preventing any subsequent backward movement of the rotor to its original position.

10. A fuze for rotatable projectiles comprising the combination of a casing, a ring pin axially mounted therein and movable relative thereby along the said axis, a projectile actuating charge mounted in the casing along the axis of movement of the firing pin and spaced therefrom, an unbalanced rotor eccentrically mounted relative to the rotational axis of the fuze, a plurality of detonators circumferentially disposed on the rotor and movable into and out of a position intermediate the firing pin and projectile actuating charge upon rotation of the rotor, a weight attached to the rotor to angularly shift the center of mass thereof, means to remove the weight and thereby induce the rotor to turn when the fuze is rotating and thereby move the detonators into said intermediate position, means movable into and out of the path of travel of the rotor and engageable therewith to limit the angle of rotation of the said rotor, said means being so positioned that upon engagement with the rotor, one of the detonators is in the said intermediate position, a rst armed locking means Carried by the rotor and lockably engageable with the casing wall when the said one detonator is moved into said intermediate position, said engagement preventing the backward. movement of the rotor to its original position, a member extending inward from the casing wall into the path of travel of the rotor beyond the position of the said movable means, to contact the rotor and arrest further movement thereof, said member being so positioned that upon said Contact, another of said detonators is in the said intermediate position, and a second armed locking means carried bythe rotor and locliably with the casing wall when the said another detonator is moved into said intermediate position, and thus prevent any backward movement of the rotor.

11. A fuze for rotatable projectiles comprising, the combination of a casing, a ring pin axially mounted therein and movable relative thereto along the said axis, a projectile actuating charge mounted in the casing along the aX-is of movement of the ring pin and spaced, beyond the movable distance of the ring pin, an unbalanced rotor rotatably positioned between the said pin and said 12 charge and eccentrically mounted relative to the rotational axis o the fuze and on an axis substantially parallel thereto, a detonator carried by the rotor and movable into and out of a position intermediate the firing pin and projectile actuating charge, within the movable distance of the ring pin, upon rotation of the rotor, Ia weight attached to the rotor vto shift the center of mass thereof to a position along a new radial vector with respect to `the rotational center of the rotor, means to release the weight and thereby induce the rotor to turn when the fuze is rotating and thereby move the detonator into said intermediate position and locking means engaging the 5' iiring pin to prevent the movement thereof prior to firing the projectile, said locking means being disengageable by the centrifugal force incident to flight.

FRANK B. HALE.

References Cited in the le o this patent UNITED STATES PATENTS Number Name Date 1,472,941 ASchneider Nov. 6, 1923 1.550,977 Lukens Aug. 25, 1925 2,129,692 lI-Iottinger Sept. 13, 1938 2,435,415 Thompson Feb. 3, 1948 2,472,366 VBrede June 7, 1949 FOREIGN PATENTS Number Country Date 34,024A France Oct. 23, 1928 891,973 France Dec. 17, 1943 

